Windshield wiper motor



March 3, i936. y R. A. Pow/ELL. ET AL 2,@32,75

WINDSHIELD WIPER MOTOR Filed Aug. 20, 1932 2 Sheets-Sheet l March 3,1936. R. A. FGWELL- ET A| 2,032,735

wINDsHIELD WI-PER MQTOR Filed Aug. 2o, 1932 2 sheets-sheet 2 PatentedMar. 3, 936

UNITED STATES PATENT OFFICE WINDSHIELD WIPER MOTOR Application August20, 1932, Serial No. 629,704 In Australia July 19, 1932 3 Claims.

' This invention has 'reference to an improved windshield wiper motorfor automobiles and the like and has been devised to provide vawindscreen wiper motor that will operate efficiently under all workingconditions, the wiper being of the type wherein the movement obtained bythe pulsations of a resilient and/or flexible diaphragm is convertedvinto an arcuate reciprocating motion on the part of a wiper arm mountedin the usual manner on the surface of a windshield.

The object of our invention is to provide a highly durable and efcientwindshield wiper motor comprising essentially a recessed' vacuum chamberhaving disposed therein a flexible diaphragm, the chamber havingexterior snapover valve mechanism associated therewith to co-act withthe diaphragm spindle to subject each side thereof alternately to vacuumto create a pulsating movement to the said diaphragm while means areincorporated with the spindle of the said diaphragm to convert thereciprocating motion caused by the pulsations into a partial rotaryreciprocating motion which is imparted to a wiper .arm disposed in theusual position in relation to a windshield thereby eiecting the arcuatereciprocation of the said arm to remove the moisture from the saidscreen or shield and means are included to manually control theoperation of the wiper motor for starting and stopping purposes, kandduring the stopping operation return the wiper arm to a normalinoperative position clear of the vision of the driver.

Other objects and features of the improved wind screen wiper will beapparent from the foregoing description in relation to the attacheddrawings in which:-

Figure 1 is a View in side elevation of our improved windshield wiper inthe assembled position.

Figure 2 is a front elevation of the Wiper motor, `and Figure 3 is aplan thereof.

Figure 4 is a vertical central section of the wiper motor.

Figure 5 is an inverted plan of the wiper motor.

Figure 6 is a central section of a modified valve `arrangement in thewiper motor.

Figs. 'l and 8 are details of the manually operable valve mechanism ofthe wiper motor;

Fig. 9 is a detailed View in front elevation, partly in section, of thesnapover valve mechanism; while Fig. 10 is a perspective view of thediaphragm '55 rod illustrating the 4rack yand slot formed therein.

Fig. l1 is a fragmentary view, in section, of the motor, illustratingportions of the valve mechanism and fluid passages. l

According to one form of carrying the invention into practical effect,the motor for the wiper consists, inter alia, of a recessed vacuumchamber 5 in which a diaphragm 6 is disposed as the actuating member ofthe wiper arm.

The diaphragm YIi is composed of any suitable ilexible material and isshaped to correspond with the outline of the respective sections of thevacuum chamber which is formed of two correspondingly shaped-andldivided sections 8 and 9, the outer edges 9a of which are flattened andsecurely fastened together by means of spaced studs I0.

As illustrated in Figure 4, it will be noticed that the outer peripheraledges II of the diaphragm 6 are seated between the united sections 8 and9 of the vacuum chamber 5 to form a gasket for same and thereby seal theinterior of the vacuum chamber.

The vacuum chamber 5 may be shaped in the manner illustrated in theaccompanying drawing while the upper and lower exterior surfaces I2ofthe chamber are substantially ilat to have mounted thereon the controlmechanism and valves as will be hereinafter described.

Each divided and complemental section 8 and 9 of the vacuum chamber iscorrespondingly shaped and provided with an internally tapered wall I3which actually denes and limits the movement of the diaphragm.

The diaphragm 6 is attached to plates I4, the upper of which is formedintegral with an open cylinder I5 which depends into a restrictedauxiliary .casing I6 formedon the underside of the vacuum chamber 5 andopening into the lower complemental section 9, the plates I4 beingattached to the diaphragm 6 by means of spaced screws I'lIa or the like.

'I'he box of the depending cylinder I5 has attached thereto the lowerend of a centrally disposed vertical rod I1 which extends upwardlythrough a guide bearing I8 formed in the upper section 8 of the vacuumchamber 5, while the upper end of the rod'l'l is formed with a racksurface I9 of predetermined length to engage with an oscillatingmutilated pinion 20 sup- 50 ported on a transverse spindle 2| carried inbearings 22 mounted on the upper flat surface I2 of the vacuum chamber.

The spindle 2| of the oscillating pinion 20 is extended through theframe23 of the windshield 55 24 to receive the squeegee wiper arm 25 in theusual manner.

The upper surface I2 of the vacuum chamber 5 is attached to the spacedright angled lugs or brackets 26 which are adapted to be secured to theframe 23 of the windshield 24 to retain the motor of the wiper in anoperative position as illustrated in Figure 1.

The lower end of the bearing surface I8 within the vacuum chamber isthreaded to receive the screw cap and gland 21 which are disposed aroundthe rod I1 to prevent leakage of air during the operation of thediaphragm 6 and its rod I1 as will be described.

'Ihe upper extremity of the diaphragm rod I1 is formed with a recess 28which is of equal length and oppositely disposedin relation tothe racksurface I9, the said recess 28 being substantially rectangular and of adepth to permit a,v

projection to extend and seat therein.

The recess 28 is in constant engagement with a right angled projectionor lug 29 formed on one end of pivoted and inclined spring controlledyokes 36 and 3|, each yoke being united at one end and the said yokes 30and 3| being adapted to pivot on a common centre line, being inclinedtowards each other with their inner ends formed with grooves 33 toengage with each side of the upper flattened portions 35 of a channelshaped bracket 36 mounted on the upper flat surface I2 of the vacuumchamber 5. -Y

The grooves 33 formed in' the inner ends of the yokes 30 and 3|'areadapted to seat on each edge of the ilattened portions of the bracket asillustrated in Figures 1 and 3, with the said yokes 30 and 3| inclinedtowards each other and united lby a tension spring 31 disposed betweensaid 6 while the other yoke 3| has its outer end reduced to seat inthebifurcated end 38 of a bell crank 39 which is pivoted as at 39a to anupraised portion or block 40 formed on the outer casing of the `upper'complemental section 8 of the vacuum chamber 5 while the other and lowerend of the bell crank 39 is secured to a slide valve 4| of suitabledimensions which operates over a valve surface 42 formed on the outersurface of the vertical block 40, the valve surface 42 being providedwith three spaced ports 43, 44 and 45, the centre port 44 comprisingthevacuum supply port, While the ports 43 Aand 45 on each side thereof areprovided with tubular leads 46 and 41, respectively, which extend toports 46a and 41a in each divided member 8 and 9 forming the vacuumchamber. I

The slide valve 4| is of` such an area that it covers or selects two ofthe ports 43and 44, or 44 and 45 atV one time whereby vacuum is `passedfrom the centre port toone ofthe side ports 43 or 45 to draw air fromone side of the diaphragm 6 and as the slide valve 4I reciprocates in amanner to be hereinafter described, therefore air is drawnV alternatelyfrom each side of the diaphragm 6. n

The vacuum supply port 44 has a tubular lead 50 to a manually operatedvalve 5| disposed on the underside of the vacuum chamber 5; this valve5I comprises a slide Vmember or blade 52 which is seated in a block'53formed on the underside of the vacuum chamber and the outer end of theblade or slide member 52 is formed with a knob 54 for manual operation.

The valve surface 55 within the block 53 is formed with three spacedports 56, 51 and 58 (Fig. 5), the centre one 51 of which extends into apassage 51a leading to a pipe 51b which is connected to the main vacuumsupply such as the intake manifold of the engine, while one port 56communicates with a lead 58 extending to the vacuum supply port 44formed in the valve surface 42 over which the slide valve 4Ireciprocates as previously described.

'I'he other port 58 of the manually operated valve has a lead 60directly to a port 6I in the tubular casing I6 in the casing |6a; whichis integral with the lower side of the main vacuum chamber 5 to receivethe hollow cylinder I5 to l which the rod I1 of the diaphragm 6 isattached as previously described.

The upper surface of the casing I 6a extends for a limited distance intothe lower section 9 as illustrated in Figure 4 and at its upperperipheryis Vformed with an internally rtapered rim 62 upon which the diaphragm 6is .adapted to seat when the wiper is in an inoperative position.

The seating of the diaphragm 6 is' achieved by means of the annularclearance of material 64 which is maintained on the diaphragm 6 aroundthe walls of the hollow depending cylinder I5, the clearance 64 beingleft between the walls of the cylinder I5 and the adjacent edges of theunderside plate I4 which secures the said diaphragm 6 to the upperintegral plate or :flange I4 of the cylinder I5 as illustrated more.particularly in Figure 4. c.

The ange of the hollow cylinder I5 which comprises the upper diaphragmplate I4 is undercut as at 65 above the clearance 64 between the hollowcylinder I5 and the underside plates .to facilitate the grip of thediaphragm on the rim 62 when same is in an inoperative position .whichoccurs when air is drawn from the lower restrictedchamber I6 whichthereby draws the diaphragm 6 downwardly together with the hollowcylinder I5 which seats in the restricted chamber I6 and causes thematerial of the'diaphragm in the clearance 64 to seat tightly on the rim62.

The operation of the windshield wiper is'as follows:- Y

The manually operated control valve 5| is set whereby its slide or blade52 covers the main intake port 51 and the supply port 56 which leads tothe valve surface 42 on the block disposed on the upper surface of thevacuum chamber whereby vacuum is delivered from the main supply such asthe intake manifold past the manual control valve 5| and thence to thecentral port 44 of the slide valve 4I and according to which port(either 43 or 45) of the valve surface 42 is covered by the slide valve4I in conjunction with the supply port 44, air is drawn through thetubular lead from the vacuum chamber 5 on either side of the diaphragm 6which causes the said diaphragm to move alterf' nately into thecomplemental sections 8 and 9 Y 29 of the inner yoke 30, same is causedto pivot and during the initial movement of the pivot action the spring31 is tensioned and energized whereby on the continued pressure of theend of the recess 28 on the lug 29, the spring causes a sudden snap overmovement which pivots the yokes 3U and 3| inversely on their commoncentre, such pivot action imparting a simultaneous 'energized movementto the bell crank 39 which passes the slide valve 4I across to cover theother open vacuum supply port to thereby draw .air from the other sideof the vacuum chamber 5 which causes the diaphragm 6 to expand into theopposite recess I3 and commence a similar cycle of operations.

By drawing air alternately from each side of the vacuum chamber throughthe valve mechanism described, the diaphragm 6 is caused to move intoeach section 8 and 9 of the chamber 5 in turn, whereby a continuouspulsating movement is imparted to the diaphragm 6 and its rod As the rodI1 of the diaphragm 6 is reciprocating owing to the rack I9 imparting anoscillating rotary motion to the mutilated pinion 20 the spindle 2I ofwhich has mounted thereon the squeegee wiper arm 25 and the oscillatingrotation of the mutilated pinion 20 and its spindle causes the wiper arm25 to reciprocate in an arcuate motion over the wind-screen or shield24.

In this manner, by drawing air from each side of the diaphragm 6 it iscaused to pulsate to eiect a reciprocating motion to its rod I1 which isconverted into a rotary oscillating motion by the rack I9 and pinion 20,while the spindle of the pinion imparts the arcuate reciprocating motionto the wiper arm 25 as previously described.

When it is desired to discontinue the operation of the wiper arm 25, themanually operable valve 5I is manipulated whereby the slide member 52covers the main intake vacuum port 51 and the port 58 leading to theport 6I of the restricted vacuum chamber I6 whereby air is drawn fromthis latter chamber; the diaphragm 6 is immediately drawn downwardly andthe hollow cylinder I5 enters the said chamber I6 to its maximum extenton continued suction being exerted the annular clearance 64 of thediaphragm around the upper surface of the hollow cylinder I5 is causedto impinge on the rim 62 formed on the upper periphery of the restrictedvacuum chamber casing I6a.

As the diaphragm 6 seats on the rim 62 of the casing I6a. same is sealedand the pressure therein causes the said diaphragm 6 to be held down inan inoperative position and as the diaphragm descends the wiper arm 25is caused to ascend to an upper inoperative position and it is retainedin this position by means of the inability of the diaphragm to pulsate.

In this manner when air is drawn from the restricted chamber I6 thediaphragm becomes inoperative while the wiper arm 25 through the mediumof the gearing associated with the rod I1 of the diaphragm 6 is returnedto its upper normal position where it is retained until required forfurther use.

In lieu of the valve arrangement for the diaphragm 6 when inoperative asillustrated in Figure 4 it has been found during experiments thatsatisfactory results may be obtained by a valve arrangement asillustrated in Figure 8 in which a floating valve 15 is attached to theunderside of the diaphragm cylinder I5.

A Windshield wiper constructed and arranged and operating in accordancewith this invention is of great utility for the reason that there is nopossibility of leakage occurring from the vacuum chamber 5 in which theflexible diaphragm 6 operates owing to the rod I1 of the diaphragmhaving only one entry into the said chamber 5, whereas wipers at presentemployed have two bearing surfaces and openings into the vacuum chamberwherein the leather actuator operates which, after continuous operation,causes the bearing surfaces to become worn and permit a natural leakageto occur with consequent loss of power in the motor of the wiper.

Furthermore, the gearing for the rod I 1 of the diaphragm 6 in a wiperconstructed in accordance with our invention is disposed outside of thevacuum chamber 5 and the wiper arm 25 itself is driven by the saidgearing from the rod of the diaphragm whereby little or no thrust has tobe taken by the diaphragm or its rod I1 but with Wipers at presentemployed, the wiper arms are mounted on the spindles of the actuatorscausing a thrust on one side thereof in the vacuum chamber whereby lossof power is incurred in the wiper and the leather actuator becomes wornand ineiective in operation.

Although we have described and illustrated one embodiment of theinvention, it will be obvious that any suitable working improvements andpractical mechanisms may be incorporated with our improved wiper withoutdeparting from the ambit of the invention.

What we claim as our invention and desire to secure by Letters Patentisz- 1. In a wind shield wiper motor, a casing comprising twocomplemental sections, a diaphragm located in said casing, a rodattached to said diaphragm, means actuable by said rod to operate awiper arm, snap-over valve mechanism mounted on said casing to beoperated directly from said rod to Withdraw air from each side of saiddiaphragm, an open cylinder attached to said diaphragm and the lower endof the diaphragm rod, a restricted casing formed in the lowercomplemental section of the casing in alignment with the open cylinder,said restricted casing having a port therein, a fluid passage connectingsaid port to communicate with a valve-controlled source of vacuum, a rimformed on the upper end of said restricted casing, and an annularclearance disposed around the open cyl:- inder to permit the diaphragmmaterial in said clearance to impinge on the rim when air is withdrawnfrom the restricted chamber.

2. In an improved wind shield wiper motor, a casing comprising twocomplemental sections, a flexible diaphragm located between the comple'-mental sections of said casing, central plates attached to saiddiaphragm, an open cylinder formed integral with the upper plate, a rodattached to said cylinder, an annular clearance around said cylinderbetween the lower plate to provide an exposed annular section ofdiaphragm material, a restricted casing formed in the lower complementalsection of the main casing in alignment with the cylinder, saidrestricted casing having a port therein, in communication with a valvesurface connected to a source of Vacuum, a manually operable valveassociated with said valve surface, a valve seat in the upper peripheryof the casing to receive the exposed annular section of the diaphragmwhen air is withdrawn from the restricted casing to prevent movement ofthe diaphragm and gearing included with the rod -of said diaphragm tooperate a 'Wiper arm and to return the same to an upperinoperativeposition While said diaphragm is inactive.

3. Invan improved Wind shieldfwiper motor, a

casing, a diaphragm, located in said casing and dividing it into twocompartments, a rod attached to said diaphragm to operate a. wiper arm,snap'- over mechanism operated directly from said rod, a lslide valveconnected with said mechanisrm a valve seat located below said valve,said valve seat having a series of ports therein, independent fluidpassages emanating from said ports to communicate respectively with eachside of the diaphragm, a valve seat formed on the underfaosaffis .sideof said and a supply port therein,"a `manually operable slide memberadjustable in relation to the last-mentioned valve seat, saidvalve seathaving a series of other ports, independent fluid passages connectedwith v said series ports and communicating respectively with thefirst-mentioned seat, a. source of suctionyon one side only of thediaphragm, said slide member being adapted tov cover two portscontinuously to direct suction either to the slide valve or to one sideonly of the diaphragm for Y the purposes herein specified. n

REGINALD ARTHUR POWELL. ROY WILLIAM NEWTON.

